Diazo preparations and process of making same



Patented Mar. 5, 11935 UNITED STATES PATENT OFFICE v 1,993,433 mazo PREPARATIONS AND rnocnss OF MAKING SAME Grald Bonhote, Basel,

Switzerland, assignor to the firmed Society of Chemical Industry in Basic, Basel, Switzerland No Drawing. Application m..- 16, 1934. Serial- In Switzerland September 27,

1 Claim. (Cl. 260-11) I In application Serial No. 705,954 it has been pointed out that in the production insoluble azo-dyestufis on the fiber dyeings are in many cases also obtained which possess a surprisingly 5 good iastness to washing and soda boiling by using a diazotized aromatic ortho-aminocarboxylic acid as diazotizing component.

It has now been found that the diazotized aromatic ortho-aminocarboxylic acids may be separated from their solutions by various precipitants, and yield valuable diazo preparations. This result could not be expected at all, since up to now,

nothing has been known about the separation oisuch diazo compounds. Moreover, the diazo compounds of other aromatic carboxylic acids, such as those from metaor para-aminobenzoic acids, can only be separated with bad yields. As precipitants there come into consideration products having a salting out action, such as for example sodium chloride, or products yielding salts or complex salts with .diazo compounds, such as aromatic sulionic acids, aromatic suliono-carboxylic acids, acylated aminosulionic acids, zinc chloride, cadmium chloride, salts of the hydro- .fluoboric acid etc. The separated diazo compounds have very probably the characteristic iormula coon wherein It means an aromatic radical oi. the or naphthalene series, wherein further the diam-group and-the carboxyl-group stand in ortho-pcsition .to-each other, and wherein nnally the anion may be that or. the hydrochloric acid or'the hydrobromic acid (it necessary in combination with a salt inclined to term complex salts, such'as zinc chloride or thatoi fan aromatic sulionic acid, such as the anion oi! the naphthalene-lzb-disulionic acid or the para chlorobenzene sulionic acid. They are chara 104 was l-amino-d-acetylamino-z-benaolc by their stability. They may be used assuch, but they can alsobe mixed with the usual dyeing assistants. such as aluminium sulrate, sodium sulfate, sodium acetate sodium alkali salts of the aromatic sulIonlc acids, and the like. 'lhe following illustrate the invention,thepartsbeingbyweightunless otherwise stated:

- Example 1 acid are diazotized by introducing into 1200 parts by volume or water, 300 parts of ice and 250 parts by volume of hydrochloric acid oi! per cent. strength, followed by addition or 200 parts by volume 01' a 5-N sodium nitrite solution. parts 0! common salt are then introduced into the diazo solution. The hydrochloride oi the 1-diazo-4-acetylamino-2-benzolc acid of the probable formula e1 NEN nu coon o=o in.

separates in the form of white crystals, giving a very good yield. The crystals are filtered oil.

and dried at 30-40 C. in a vacuum. The product thus obtained is stable and very easily soluble in water.

Example 2 some sodium chloride. The yield is very good. Example 4 tion may be completed yet by the addition of 181 part's oi 1-amino-5 'ethoxy-2 benzoic acid are diazotized as describe the diazo solution there are now introduced 250 parts of sodium-'paraechlorobenzene sulionate.

and 200 parts 01' common'salt. The stabilized diazo compound crystallizes in the form 01 colorless crystalsgiving a good yield.

Exam les 151 parts of 1-amino-5-methyl 2-benzoic acid areidiazotized as described in Example 1. The diazo compound c by addition of 200 parts 0! sodium 1:5 naphonate to in Example 1.- Into the clear diazo solution, giving a very good yield.

Example 6 182 parts of 1-amino-5-nitro-2-benzoic acid are dissolved in 2000 parts by volume of hot water, mixed with 250 parts-by volume of hydrochlonc acid of 30 per cent; strength, cooled to 5 0., and diazotized after addition or 200 parts by volume of a. 5-N sodium nitrite solution. The stabilized diaz'o compound separates by addition of 200 parts of sodium iii-naphthalene sulfonate in the form of yellow-brown crystals.

Example 7 187 parts of 2-amino-3-naphthoic acid are diazotized in the usual manner in 2000 parts by volume of water, and the zinc diazonium compound is separated by addition of 200 parts of zinc chloride and some common salt. The yield is very good.

What I claim is: The zinc chloride double salts of diazo compounds of the general formula free diazo compounds.

GERAID BONHOTE. 

